In the mining and civil construction industries hard materials such as rock and concrete are fractured and/or removed using explosives and propellants hereafter referred to in general as “energetic materials”. Typically blast holes are drilled in the hard material and filled with the energetic material which is subsequently detonated. The energetic materials may be provided in form of granules, a powder or a liquid that typically are filled directly into the blast holes.
Alternatively, tubes in which the energetic materials are packaged and sealed are used. Such tubes typically are composed of a plastics material and offer more flexibility. For example, they can be positioned within a blast hole or at any other position at which an explosion is required. The tubes can be charged with the energetic material by pressing the energetic material into the tubes in a variety of known ways including blow loading, augering or gravity feed.
The process of charging the tubes with the energetic materials is not without danger. Mechanical friction caused by tools used for charging the tubes may result in development of heat which could detonate the energetic materials. Further, contact of tools with each other could result in sparking which has the same danger. In addition, the charging techniques known to date have the disadvantage that it is relatively difficult to remove air from the interior of the tubes during the charging process and consequently it is relatively difficult to charge the tubes so that the energetic materials are densely packed within the tubes.
There is a need for technological advancement.